A red tide bloom has waxed and waned along Florida’ southwestern coastline for months, dating back to late 2001. As recently as March 1, 2002, high concentrations of <i>Karenia brevis</i> were located along the Lee County and Collier County shorelines. In-water measurements revealed there are more than 1 million cells of the algae per liter of water—a level at which the organism become highly toxic to fish and shellfish in the area.This true-color image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA’s Terra satellite, on February 17, 2002. Sensor: Terra/MODIS. Data Start Date: 2/17/02.